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Exotic Plant Disease Threats to the New Zealand Avocado Industry and Climatic Suitability: a Review

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Exotic Plant Disease Threats to the New Zealand Avocado Industry and Climatic Suitability: a Review Pathogens 1 25 was funded through a grant from The Ministry of spray drift. NZ Kiwifruit, Feb: 18-19. for Business and Innovation under the project Holland P, Maber J, May W, Malcolm C 1997. Exotic plant disease threats to the New Zealand avocado “Protecting NZ’s Environment from Pesticide Drift from orchard spraying. Proceedings industry and climatic suitability: a review Exposure”. of the New Zealand Plant Protection Conference. Pp. 112-118. Kerry R. Everett1,* and Brad Siebert2 REFERENCES Johnson D 1995. Drift from orchard airblast Bonds JAS, Leggett M 2015. A literature review applications: Integration and summary of 1e New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Mt Albert, of downwind drift from airblast sprayers: 1993 and 1994 field studies. Spray Drift Task Auckland 1142, New Zealand development of standard methodologies and Force (SDTF) Report No. I95-004. Stewart 2New Zealand Avocado, PO Box 13267, Tauranga 3141, New Zealand a drift database. Transactions of the ASABE Agricultural Research Services, Inc. Macon, *Corresponding author: [email protected] 58: 1471-1477. MO, USA. Connell R, Woodward S, Zabkiewicz J, Moller H, Wearing A, Perley C, Rosin C, Abstract The avocado industry was established in New Zealand from several importations Hewitt A 2010. Shelterbelt interception Blackwell G, Campbell H, Hunt L 2007. dating back to 1907. Several serious pathogens found elsewhere in the world were not of agrichemicals: model and field results. Biodiversity on kiwifruit orchards: the imported. A literature review and internet search were conducted to determine what Aspects of Applied Biology 99: 443-448. importance of shelterbelts. Proceedings of the serious avocado pathogens are not present in New Zealand and the potential impact they Fritz BK, Hoffmann WC 2008. Collection 6th International Symposium on Kiwifruit, could have if they established. Relevant information was summarised for six pathogens efficiencies of various airborne spray flux Rotorua. determined to be the most serious of avocado and not known to be present in New Zealand: samplers used in aerial application research. Nufarm n.d. Driftstop. http://www.nufarm.com/ avocado sunblotch viroid (ASBVd); Pseudocercospora purpurea (cercospora spot); Raaelea Journal of ASTM international 5: 1-11. assets/37041/1/DriftStopBrochure.pdf lauricola (laurel wilt); Fusarium sp. (fusarium dieback); Phellinus noxius (brown root rot); Gaskin R, Manktelow D, Steele K 2006. Adjuvant Peterson J, Wolf T, Mazurek K, Caldwell B and Sphaceloma perseae (avocado scab). Laurel wilt, brown root rot, cercospora spot and and application technologies to minimise 2008. The movement of spray drift near a fusarium dieback could become established in New Zealand if the climate here becomes off-target drift from kiwifruit sprays. New live shelterbelt. Soils & Crops Conference, warmer but establishment of ASBVd and avocado scab (which are not restricted to hot Zealand Plant Protection 59: 217. Saskatoon, Saskatchewan, Canada, February climates) is more likely. Gaskin R, Manktelow D, May W 2007. Adjuvants 28-29, 2008. and air inclusion nozzles reduce hydrogen Raupach MR, Leys JF, Woods N, Dorr G, Cleugh Keywords Sphaceloma perseae, Pseudocercospora purpurea, brown root rot, Euwallacea sp., cyanamide spray drift in kiwifruit orchards. HA 2000. Modelling the effects of riparian Raaelea lauricola, Xyleborus glabratus, redbay ambrosia beetle, Fusarium sp., Avocado Proceedings of the 8th International vegetation on spray drift and dust: The role sunblotch viroid. Symposium on Adjuvants for Agrochemicals of local protection. Technical Report 29/00. (ISAA2007). Columbus, OH, USA, 6-9 Aug. CSIRO, Canberra, Australia. http://www.clw. 2007. csiro.au/publications/technical2000/tr29-00. Gaskin R, Manktelow D, May W 2009. Field pdf INTRODUCTION Avocados in New Zealand are affected studies to optimise spray deposits on Schep L, Temple W, Beasley M 2007. The The avocado (Persea americana) is a sub- by a number of plant pathogens, of which shelterbelts and minimise off-target drift. evaluation of hydrogen cyanamide-related tropical Lauraceous tree that produces oil rich the most common are two root invaders Report to NZ Kiwifruit Growers, Inc. SFF inquiries to the New Zealand National fruit. Avocados originate from middle America (Phytophthora cinnamomi and Verticillium Project # 06/090. July 2009. http://maxa.maf. Poisons Centre between 1990 and 2006. (Mexico, West Indies and Guatemala) and dahliae) and pathogens that cause rots in ripe govt.nz/sff/about-projects/search/06-090/ Clinical Toxicology 45: 360. avocado plants were first imported into Tauranga, fruit (Colletotrichum acutatum, Colletotrichum shelter-drift-report.pdf Schep L, Temple W, Beasley M 2009. The adverse New Zealand as seedlings in 1907 (Green gloeosporioides, Botryosphaeria dothidea, Gaskin R, Manktelow D, May B, Max S 2008. effects of hydrogen cyanamide on human 1927). Several more plants were imported to Neofusicoccum parvum (syn. B. parva) and Development of Best Practice to minimise health: an evaluation of inquiries to the New Tauranga and Wanganui in 1917, followed by the Phomopsis sp.). These pathogens have a wide host off-target drift from hydrogen cyanamide Zealand National Poisons Centre. Clinical importation of grafted avocados from California range and may have originated from infected sprays in kiwifruit orchards. New Zealand Toxicology 47: 58-60. to Gisborne and Tauranga in 1940 (White 2001). host material already present in New Zealand or Plant Protection 61: 153-158. Zhu H, Reichard DL, Fox RD, Brazee RD, Ozkan More recent importations of new rootstocks from infected avocado plant material imported in Gaskin R, Manktelow D, Cook S, May W, van HE 1996. Collection efficiency of spray and fruiting varieties from South Africa and 1907, 1917 and 1940. Most fungi that infect fruit Leeuwen R 2013. Effects of canopy density on droplets on vertical targets. Transactions of California took place since 1999. The ‘Hass’ to cause rots will also asymptomatically infect spray deposition in kiwifruit. New Zealand the ASABE 39: 415-422. variety is the most commonly grown avocado in vegetative tissue (Everett et al. 1999; Hartill & Plant Protection 66: 194-198. New Zealand and was probably imported with the Everett 2002; Everett et al. 2003). The first record Holland P, Maber J 1992. Reducing the problem batch of grafted avocados in 1940 (White 2001). of an avocado fruit rot was of C. gloeosporioides ©2018 New Zealand Plant Protection Society (Inc.) www.nzpps.org Refer to http://www.nzpps.org/terms_of_use.html New Zealand Plant Protection 71: 25-38 (2018) https://doi.org/10.30843/nzpp.2018.71.140 Pathogens 1 26 (Brien 1939), and the first record of a root disease The aim of this study was to collate relevant The main problems associated with this al. 1984). Seed transmission from ‘recovered’ was of Phytophthora cinnamomi (Zentmeyer information on serious avocado pathogens not disease are disease management costs, such as or symptomless trees can be as high as 95% 1965), then the vascular wilt pathogen V. dahliae currently present in New Zealand and their those required to ensure nursery material is (Wallace & Drake 1962). Spread by seed from (Fletcher 1976). The remaining commonly potential impact to the New Zealand avocado not infected, destroying infected trees in the fruit developing from flowers pollinated with occurring fruit rot pathogens were first reported industry if they were to establish in avocado- orchard showing symptoms, tests for detection of infected pollen (5%) was higher than from the by Boesewinkel (1982) (C. acutatum), Hartill growing regions of the country. asymptomatic infected trees, and yield reduction. pollen itself (1-4%) (Wallace & Drake 1962). (1987) (N. parvum, Phomopsis sp.) and Hartill et Presence of ASBVd can also restrict access to Foliar symptoms are more pronounced al. (1991a,b) (B. dothidea). METHODS some markets, such as the restriction of imports with increased temperature (da Graca & van Biosecurity measures for importation of An electronic literature search of Web of Science, from eight countries with records of ASBVd by Vuuren 1981b) suggesting an adaptation to hot nursery stock into New Zealand date back to CABI and Google databases was conducted on 2 Costa Rico in 2015 (Anonymous, 2015). ASBVd climates. Although New Zealand has a relatively 1889, when fumigation vaults were constructed, February 2018 using the terms avocado or Persea causes skin distortions and chlorotic patches cool climate, the viroid is expected to survive according to Helson (1966). Since as early as AND fung* or plant and pathogen*. Resultant rendering the disfigured avocados unmarketable. wherever avocado trees grow (Perez et al. 2017). 1966, imported plants were inspected at the publications were obtained and the literature ASBVd affects leaves and shoots similarly, causing Therefore, the disease could establish where New Zealand border and fumigated with methyl listed in those papers was used to access literature distortions and chlorotic patches. ASBVd can also avocados are grown in New Zealand, in the bromide if any pests were detected (Helson beyond the scope of the electronic searches. infect asymptomatically, depending on the host Northland, Whangarei, Bay of Plenty, Hawke’s 1966). Post inspection and treatment the plants References in the first author’s collection were cultivar, environmental conditions and viroid Bay and Nelson districts. were placed in post-entry quarantine for 12
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